Orlando Cruz failed Saturday in his bid to become boxing's first openly gay world champion when Terry Flanagan defeated him to defend the World Boxing Organisation (WBO) lightweight title in Cardiff.

The 35-year-old Puerto Rican Cruz had fought nine professional bouts since publicly revealing his sexuality in 2012 and hopes his example may encourage anyone else wishing to come out.

Saturday's bout was Cruz's first as a lightweight after he previously lost a world featherweight title fight against Orlando Salido in Las Vegas in October 2013.

Britain's Flanagan triumphed in Cardiff as he made a fourth successful defence of the crown he first wore in July last year, stopping his rival in the eighth round after controlling the show from the first bell.

Cruz did all he could in dancing around, his agility making the more stolid Flanagan work for his 32nd win as the latter maintained his unbeaten ring record.

For Cruz, his loss was his fifth in 31 bouts.

The bout was a slow burner before Flanagan found his range after three rounds as Cruz began to flag, taking more and more punches.

A right-hander dropped him to the canvas in the eighth and referee Steve Gray stopped the contest.

"I want to inspire the gay community by becoming a world champion on Saturday," Cruz had said Friday. "Everyone has been very supportive since I came out. I have the support of my family, friends and fans.

"When I look at my story, it makes me hopeful that more people will be inspired to come out."

Briton Flanagan said beforehand he respected Cruz's position as his own sister, Chelsea, was openly gay.

"I remember well when she came out and what it was like," said Flanagan. "She's had it hard, she came out in her teens and she's a better person for it now."

As with other sports, boxing has seen no shortage of rumours as to which well-known competitors might be homosexual.

One concerned Panamanian Panama Al Brown, the first latino world champion who won flyweight and bantamweight titles in the 1940s.

Others revolved around bisexual multiple world champion Emile Griffith from the US Virgin Islands and Cuban Benny Paret. They infamously fought a title bout in 1962 where at the weigh in Paret made homophobic comments.

Griffith knocked out the Cuban, who never regained consciousness.

Flanagan is now reportedly looking to fight the winner of a rematch between another Briton, Anthony Crolla, and Venezuela's Jorge Linares, who ousted Crolla in September to win the WBA lightweight title.

But his next defence is more likely to be against Puerto Rico's Felix Verdejo, who is recovering from a summer motorcycle accident.